Associations of different type of physical activity with all-cause mortality in hypertension participants

Few studies explored the association of different type of physical activity with all-cause mortality in hypertension (HBP) participants. A retrospective cohort analysis was performed using National Health and Nutrition Examination Survey (NHANES) data to explore association of moderate-intensity physical activity (MPA), vigorous-intensity physical activity (VPA), sedentary behavior with mortality in HBP individuals. Among 10,913 HBP participants followed for a median of 6.2 years, VPA was not associated with a reduction in all-cause mortality compared to participants without VPA in multivariate Cox survival analysis. MPA was linked to lower all-cause mortality at durations of 0–150 min/week (HR, 0.72; 95% CI 0.58–0.88), 150–300 min/week (HR, 0.71; 95% CI 0.52–0.96), and > 300 min/week (HR, 0.61; 95% CI 0.49–0.77) compared to no MPA. Sedentary behavior of 6–8 h/day (HR, 1.35; 95% CI 1.15–1.59) and > 8 h/day (HR, 1.55; 95% CI 1.34–1.79) were associated with increased mortality risk versus < 6 h/day. Further research is needed to explore whether VPA can improve outcomes for HBP individuals and to determine the optimal duration of VPA.MPA is linked to lower mortality risk, indicating its potential as the best physical activity intensity for HBP individuals.

HBP participants are subjects who self-report having been diagnosed with HBP by a physician.The method for measuring BP is as follows: after resting quietly in a sitting position for 5 min and determining the maximum inflation level, three consecutive BP readings are obtained.If a BP measurement is interrupted or incomplete, a fourth attempt may be made, the average of the three BP readings is calculated.NCHS has established a linkage between various population surveys and death certificate records from the National Death Index.The follow-up period was calculated in person-months, starting from the interview date to the event of death, loss to follow-up, or the end of the mortality follow-up period on December 31, 2019.

Time of physical activity
Data on physical activity time were gathered through participant responses to the Global Physical Activity Questionnaire (GPAQ).The GPAQ has been previously validated to collect information related to work activity and recreational activities 14 .During face-to-face interviews, participants were asked to detail the frequency and duration of MPA and VPA during a typical week.The time of physical activity was calculated by summing both work and recreational activities.MPA was categorized into four levels (0 min/week, 0-150 min/week, 150-300 min/week, > 300 min/week) and sedentary activity time was categorized into three levels (< 6 h/day, 6-8 h/day, > 8 h/day).

Sociodemographic characteristics and covariates
The study participants provided a range of demographic information, including age, gender, body mass index (BMI), smoke history and racial categorization (Mexican American, Other Hispanic, Non-Hispanic White, Non-Hispanic Black and Other Race).Educational levels were categorized into four groups: less than high school, high school graduate, some college or associate degree, and college graduate.Marital status was classified into three categories: never married, married or living with a partner and separated or divorced or widowed.The ratio of family income to poverty level was categorized as < 1, 1-3, or > 3. Additionally, vital biomarkers including albumin and creatinine were obtained from the principal NHANES dataset.Pre-comorbidities were identified including diabetes mellitus (DM), coronary heart disease (CHD), heart failure (HF), hypercholesterolemia, stroke, chronic bronchitis and liver diseases.The presence of these conditions was determined based on physician diagnoses documented in the NHANES data.

Statistical analysis
We accounted for the complex survey design of NHANES by incorporating sample weights, clustering, and stratification.To achieve nationally representative estimates, the original survey weights were adjusted and utilized in the analysis, taking into account the appropriate adjustments 15,16 .Initially, we examined the association of VPA, MPA and sedentary activity time with all-cause mortality among all HBP participants.VPA, MPA and sedentary activity were all included as covariates in the Cox survival analysis.Adjustments were made for gender, age, race, marital status, educational level, family income level, smoke history, albumin, creatinine levels and the presence of comorbidities such as CHD, stroke, chronic bronchitis, liver conditions and high cholesterol.Statistical significance was defined as P ≤ 0.05.In the subsequent sections, we conducted association between MPA and all-cause mortality across various subgroups defined by the presence of VPA and different durations of sedentary activity.In sensitivity analysis, we excluded patients with a follow-up duration of less than 1 year, as well as those who died due to accidental events, and re-analyzed the data accordingly.Missing data were addressed using the multiple imputation technique, with less than 3% missing values for most variables, except for BMI (5.6% missing), albumin (9.67% missing) and creatinine (9.69% missing) 17 .

Discussion
In our population-based study, we explored the correlation between different durations of VPA, MPA, sedentary activity and mortality among participants with HBP, utilizing data from NHANES, a nationally representative sample.Longer duration of MPA and shorter duration of sedentary activity were associated with a decrease in mortality in both univariate and multivariate Cox analyses.VPA was associated with a reduction in all-cause mortality compared to participants without VPA in univariate Cox survival analysis.As compared to the participants without VPA, the participants with VPA were characterized by a younger age, lower BMI, a higher proportion of males, and a greater percentage of individuals with an education level of high school or above.Furthermore, participants with VPA had lower rates of comorbidities including HF, CHD, diabetes, stroke, hypercholesterolemia, chronic bronchitis and liver diseases.In the multivariate Cox proportional hazards analysis, considering Vol:.( 1234567890 www.nature.com/scientificreports/ the effects of MPA, sedentary activity and other covariates simultaneously, we found that the presence of VPA was not associated with a reduction in all-cause mortality.
Vigorous-intensity physical activity has been shown to have a beneficial impact on the prognosis and mortality of HBP patients, but there are also different opinions or controversies in some studies.A study reported that compared with the least active group, 75-150 min/week of VPA or more was associated with few further benefits, even weakening the cardiovascular benefits.A relatively short duration of VPA was probably more beneficial than a longer duration of VPA 7 .Two recent analyses indicate reductions in mortality across the general populace could potentially be attained with VPA quantities less than those presently advised, yet neither study delved into the impact of prolonged VPA exposure 18,19 .The findings suggest that minimal VPA levels might confer greater benefits, hinting that the ideal VPA dosage may fall below current guidelines.VPA may trigger a short-term surge in BP, with HBP individuals possibly experiencing an exaggerated BP reaction to physical activity 20 .The propensity for atherosclerosis formation escalates in HBP patients, where sudden BP spikes could provoke the rupture of atherosclerotic plaques and lead to acute arterial thrombosis, thereby heightening the risk of cardiovascular incidents 6,21 .These observations imply the necessity of a more judicious approach to physical activity recommendations for those with HBP.
A substantial body of research has confirmed that longer durations of MPA and shorter durations of sedentary activity are associated with a reduction in all-cause mortality among HBP patients [22][23][24][25] .Our study results are in line with previous research, and we discovered some interesting findings in our subgroup analyses.In the subgroup without VPA, longer durations of MPA were still associated with a reduction in all-cause mortality among HBP patients.However, in the subgroup with VPA, longer durations of MPA were almost not associated with lower all-cause mortality, with only durations > 300 min/week showing statistical significance.We www.nature.com/scientificreports/speculate that the possible reason is that participants engaging in VPA generally have better physical function and exercise capacity, with fewer comorbidities such as HF, myocardial infarction and chronic bronchitis, which impact lifespan.Therefore, in a population with generally longer survival, different durations of MPA did not show differences, and statistical analysis was also deemed meaningless.
In the subgroups with varying durations of sedentary activity, we observed that individuals with longer sedentary activity times benefited more from MPA.From the HR, the benefits were greatest in the subgroup with more than 8 h per day of sedentary activity, followed by the 6-8 h per day subgroup, and were least in the subgroup with less than 6 h per day of sedentary activity.This suggests that individuals with longer durations of sedentary activity could improve their prognosis by engaging in MPA.MPA can effectively counteract the adverse effects of prolonged sedentary activity, thereby yielding benefits.Studies collectively support the notion that engaging in MPA is a viable and effective approach to mitigating the negative health impacts of prolonged sedentary behavior [26][27][28] .It's also important to acknowledge that shorter sedentary times may imply higher total physical activity, influencing outcomes, suggesting that the mortality benefits associated with MPA could also reflect a generally more active lifestyle.
Several limitations should be acknowledged.We did not explore the impact of different types of exercise on BP levels.Time of MPA and VPA were assessed using a single self-reported measure, which is susceptible to recall bias and potential differential misclassification.Information on medication treatment for patients with HBP was not collected.The observational nature of the study imposes limitations related to residual confounding, necessitating cautious interpretation of the associations as indicative rather than causal.The relationship between VPA and all-cause mortality still needs further exploration, as our study is retrospective and cannot establish causality.Furthermore, our study classified VPA based on its presence rather than varying durations, leaving the relationship between different lengths of VPA and all-cause mortality unclear.
Our findings underscore the association of MPA with reduced all-cause mortality among individuals with HBP.Notably, VPA did not show a direct association with mortality reduction.Our study also revealed an interaction between MPA and sedentary behavior, indicating that the benefits of MPA are pronounced in those with longer time of sedentary behavior.These findings suggest that promoting MPA, alongside strategies to reduce sedentary time, could be a crucial component of public health recommendations and clinical guidelines for managing HBP and enhancing longevity.

Conclusions
MPA is linked to lower mortality risk, indicating its potential as the best physical activity intensity for HBP individuals.Further research is needed to explore whether VPA can improve outcomes for HBP individuals and to determine the optimal duration of VPA.

Figure 1 .
Figure 1.Flow diagram of study sample selection.

Table 1 .
Baseline characteristics of HBP participants stratified by whether had VPA from NHANES.All estimates accounted for complex survey designs.All numbers in the table are weighted percentages or means.HBP hypertension, SBP systolic blood pressure, DBP, diastolic blood pressure, VPA vigorous-intensity physical activity, MPA moderate-intensity physical activity, NHANES National Health and Nutrition Examination Survey, BMI body-mass index, DM diabetes, HF heart failure.CHD coronary heart disease.

Table 2 .
Estimated association of VPA, MPA and recreational time with all-cause mortality in HBP participants.Survey sample weights were taken into consideration in the Cox models accompanying the NHANES data.Covariates in Model 1 included VPA, MPA, recreational time, gender, age, race, marital status, educational level, family income level, smoke history.Model 2 also included albumin, creatinine levels and the presence of comorbidities including CHD, stroke, chronic bronchitis, liver conditions and high cholesterol.HBP hypertension, VPA, vigorous-intensity physical activity, MPA moderate-intensity physical activity.

Table 3 .
Subgroup analysis for association of MPA with all-cause mortality in HBP participants.Survey sample weights were taken into consideration in the Cox models accompanying the NHANES data.HBP hypertension, VPA, vigorous-intensity physical activity, MPA, moderate-intensity physical activity.